Organic el lighting panel substrate, method for manufacturing organic el lighting panel substrate, organic el lighting panel, and organic el lighting device

ABSTRACT

Disclosed are an organic EL lighting panel substrate and associated manufacturing method that can improve the manufacturing efficiency of an organic EL lighting panel substrate to reduce the cost and can achieve an organic EL lighting panel of excellent yield and reliability. The organic EL lighting panel substrate includes: a translucent substrate; a transparent electrode; and an auxiliary electrode. The transparent electrode is arranged on a surface of the translucent substrate and the auxiliary electrode is electrically connected to the transparent electrode. The organic EL lighting panel substrate further includes: an insulating layer at the position corresponding to an electrode lead-out part of an upper electrode of an organic EL layer that forms an organic EL lighting panel, the upper electrode being provided above the translucent substrate in such a manner as to face the transparent electrode; and a conductive layer between the translucent substrate and the insulating layer.

TECHNICAL FIELD

The present invention relates to an organic EL lighting panel substrate,a method for manufacturing an organic EL lighting panel substrate, anorganic EL lighting panel, and an organic EL lighting device.

BACKGROUND ART

In organic EL (electroluminescence) lighting panels used for organic ELlighting devices, generally, transparent electrodes formed oftransparent conductive materials such as ITO, ZnO, SnO₂ (NESA glass),and the like are used as electrodes at the side where the light is ledout. Since the volume resistivities of the above-described transparentconductive materials are high, the sheet resistances become high in thecase where the materials are used as thin films. Therefore, in anorganic EL lighting panel using the above-described transparentelectrode, a voltage drop due to increase in wiring resistance is causedas distanced from a transparent electrode end (feed terminal from powersupply), i.e., as approached toward the inside (center) of the organicEL lighting panel. When the voltage drops at an electrode part, itcauses an electric power loss at the electrode part as well as decreasesin luminance and chromaticity, and thereby the luminance uniformity andchromaticity uniformity within a surface of an organic EL lighting panelare decreased. The above-described decreases in luminance andchromaticity are caused because an organic EL element is anelectroluminescent type element, an electric field at the center of theelement becomes smaller than that at the vicinity of a feed terminalbecause of a voltage drop, the injection efficiency of a carrier(hole/electron) is decreased, and the luminous efficiency is decreased.

Hence, for reducing the wiring resistance at the transparent electrodeside, the provision of an auxiliary electrode on a transparent electrodehas been considered (see, for example, Patent Documents 1 and 2). Atthis time, an end-insulating layer for covering the end of thetransparent electrode is provided for avoiding the conduction between anupper electrode (in the case where the transparent electrode is ananode, a cathode) provided at the upper side relative to a translucentsubstrate and a transparent electrode, and an interlayer-insulatinglayer for covering the auxiliary electrode is provided for avoiding theconduction between the auxiliary electrode and an organic EL element(see, for example, Patent Document 2).

The organic EL lighting panel is manufactured, as shown in FIGS. 9A toC, by the following steps, for example. A translucent electrode material(for example, ITO) is laminated (formed) on a translucent substrate andthe patterning using a photoresist is performed to form a translucentelectrode layer. After removing the photoresist, an auxiliaryelectrode-forming material layer is formed, and an auxiliary electrodeof a desired pattern is formed by a photolithography step or the like.Specifically, an auxiliary electrode-forming material layer is laminatedall over a translucent substrate on which a translucent electrode layeris formed, a photoresist is applied thereto, the auxiliaryelectrode-forming material layer is formed into a desired pattern by anexposure through a mask on which a desired pattern is formed, adevelopment, and an etching, and thereafter the resist on the auxiliaryelectrode-forming material layer is removed. Thereafter, aninterlayer-insulating layer for covering the auxiliary electrode and anend-insulating layer for the end of the translucent electrode layer areeach formed by a photolithography step in the same manner as describedabove. Then, an organic layer and an upper electrode layer are laminatedthereon to manufacture an organic EL lighting panel.

CITATION LIST Patent Document (s)

Patent Document 1: JP10(1998)-199680 A

Patent Document 2: JP2011-249075 A

SUMMARY OF INVENTION Problem to be Solved by the Invention

In the manufacture of an organic EL lighting panel substrate includingthe auxiliary electrode and the interlayer-insulating layer, a step offorming a translucent electrode layer, a step of patterning it into apanel shape, a step of forming an auxiliary electrode, a step ofpatterning it into a wiring pattern, and steps of forming and patterningan interlayer-insulating layer and an end-insulating layer are performedseparately. Therefore, multiple steps of photolithography andphoto-etching are required for forming the respective members, and thusmanufacturing costs including material costs and processing costs arehighly increased. As a result, the component cost as an organic ELlighting panel becomes very expensive. Moreover, there is a case inwhich the respective steps are handled in different factories. In such acase, the manufacturing efficiency is further decreased and the increasein cost is inevitable.

Furthermore, since resist residues and foreign matters often remain on asubstrate due to a repetition of a photolithography step and the like,there has been a problem that defects/problems such as a short circuitand the like are caused frequently in an organic EL panel and that theyields and reliability are decreased significantly.

Hence, the present invention is intended to provide an organic ELlighting panel substrate and a method for manufacturing the same thatcan improve the manufacturing efficiency of an organic EL lighting panelsubstrate to reduce the cost and can achieve an organic EL lightingpanel of excellent yield and reliability.

Means for Solving Problem

In order to achieve the above object, the present invention provides anorganic EL (electroluminescence) lighting panel substrate including: atranslucent substrate; a transparent electrode; and an auxiliaryelectrode, wherein the transparent electrode is arranged on a surface ofthe translucent substrate, the auxiliary electrode is electricallyconnected to the transparent electrode, and the organic EL lightingpanel substrate further includes: an insulating layer at a positioncorresponding to an electrode lead-out part of an upper electrode of anorganic EL layer that forms an organic EL lighting panel, the upperelectrode being provided above the translucent substrate in such amanner as to face the transparent electrode; and a conductive layerbetween the translucent substrate and the insulating layer.

The present invention also provides a method for manufacturing anorganic EL lighting panel substrate including: a transparent electrodeformation step of forming a transparent electrode on a surface of atranslucent substrate; an auxiliary electrode formation step of formingan auxiliary electrode so as to be electrically connected to thetransparent electrode; and an insulating layer formation step of formingan insulating layer at a position corresponding to an electrode lead-outpart of an upper electrode of an organic EL layer that forms an organicEL lighting panel, the upper electrode being provided above thetranslucent substrate in such a manner as to face the transparentelectrode.

The present invention also provides an organic EL lighting panelincluding: an organic EL lighting panel substrate; an organic EL layer;and an upper electrode, wherein the organic EL lighting panel substrateis the organic EL lighting panel substrate according to the presentinvention, and the organic EL layer and the upper electrode are providedon the transparent electrode in this order.

The present invention also provides an organic EL lighting deviceincluding the organic EL lighting panel according to the presentinvention.

Effects of the Invention

According to the present invention, it is possible to improve themanufacturing efficiency of an organic EL lighting panel substrate toreduce the cost and is also possible to achieve an organic EL lightingpanel of excellent yield and reliability.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] FIG. 1(a) is a plan view showing the configuration of anexample of an organic EL lighting panel substrate of the presentinvention (Embodiment 1). FIG. 1(b) is a cross sectional view of theorganic EL lighting panel substrate shown in FIG. 1(a) as viewed fromthe line I-I.

[FIG. 2] FIG. 2 is a cross sectional view showing the configuration ofanother example of an organic EL lighting panel substrate of Embodiment1.

[FIG. 3A] FIGS. 3A(a) to (g) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 1.

[FIG. 3B] FIGS. 3B(h) to (k) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 1.

[FIG. 4] FIG. 4(a) is a plan view showing the configuration of anexample of an organic EL lighting panel of the present invention(Embodiment 2). FIG. 4(b) is a cross sectional view of the organic ELlighting panel shown in FIG. 4(a) as viewed from the line II-II.

[FIG. 5] FIG. 5 is a cross sectional view showing the configuration ofanother example of an organic EL lighting panel substrate of the presentinvention (Embodiment 3).

[FIG. 6A] FIGS. 6A(a) to (f) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 3.

[FIG. 6B] FIGS. 6B(g) to (k) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 3.

[FIG. 7] FIG. 7 is a cross sectional view showing the configuration ofanother example of an organic EL lighting panel substrate of the presentinvention (Embodiment 4).

[FIG. 8A] FIGS. 8A(a) to (f) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 4.

[FIG. 8B] FIGS. 8B(g) to (l) show cross sectional views for illustratingan example of a method for manufacturing the organic EL lighting panelsubstrate of Embodiment 4.

[FIG. 9A] FIGS. 9A(a) to (h) show cross sectional views for illustratingan example of a method for manufacturing a conventional organic ELlighting panel substrate.

[FIG. 9B] FIGS. 9B(i) to (n) show cross sectional views for illustratingan example of a method for manufacturing a conventional organic ELlighting panel substrate.

[FIG. 9C] FIGS. 9C(o) to (s) show cross sectional views for illustratingan example of a method for manufacturing a conventional organic ELlighting panel substrate.

[FIG. 10A] FIGS. 10A(a) to (h) show cross sectional views forillustrating another example of a method for manufacturing aconventional organic EL lighting panel substrate.

[FIG. 10B] FIGS. 10B(i) to (n) show cross sectional views forillustrating another example of a method for manufacturing aconventional organic EL lighting panel substrate.

[FIG. 10C] FIGS. 10C(o) to (s) show cross sectional views forillustrating another example of a method for manufacturing aconventional organic EL lighting panel substrate.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, organic EL lighting panel substrates, organic EL lightingpanels, and organic EL lighting devices of the present invention will bedescribed in detail with reference to the figures. However, the presentinvention is not limited to the following embodiments. Note here that,in FIGS. 1 to 8, identical parts may be indicated with identicalnumerals and symbols and the descriptions as to the identical parts maybe omitted. In the figures, for convenience in explanation, thestructures of the respective components may be appropriately simplifiedand the dimensions and the like of the respective components may beschematically described and may be different from the actual dimensionsand the like.

Embodiment 1

An organic EL lighting panel substrate of the present embodiment is anexample of an organic EL lighting panel substrate including aninsulating layer at the position corresponding to an electrode lead-outpart of an upper electrode provided above a translucent substrate andincluding a conductive layer of a transparent electrode between thetranslucent substrate and the insulating layer. FIG. 1 shows theconfiguration of the organic EL lighting panel substrate of the presentembodiment. FIG. 1(a) is a plan view of the organic EL lighting panelsubstrate of the present embodiment. FIG. 1(b) is a cross sectional viewof the organic EL lighting panel substrate shown in FIG. 1(a) as viewedfrom the line I-I.

As shown in FIG. 1, organic EL lighting panel substrate 10 of thepresent embodiment includes translucent substrate 11, transparentelectrode 12, auxiliary electrode 13, and insulating layer 14 as maincomponents. Transparent electrode 12 and auxiliary electrode 13 arearranged on translucent substrate 11 in this order from the translucentsubstrate 11 side. Specifically, transparent electrode 12 is arrangedall over a surface of translucent substrate 11. Auxiliary electrodes 13are arranged on transparent electrode 12 at constant intervals.Transparent electrode 12 and auxiliary electrode 13 are electricallyconnected.

Examples of the material for forming translucent substrate 11 includeinorganic materials and organic materials. Examples of the inorganicmaterial include alkali-free glasses, soda-lime glasses, borosilicateglasses, aluminosilicate glasses, and fused silica. Examples of theorganic material include polyester resins such as polyethylenenaphthalate, polyethylene terephthalate, and the like; acrylic resinssuch as ethyl methacrylate, methyl methacrylate, ethyl acrylate, methylacrylate, and the like; alicyclic olefin resins such as a copolymer ofnorbornene and ethylene, and the like; polyethersulfone; andtriacetylcellulose. The thickness of translucent substrate 11 is notparticularly limited, and, for example, can be set appropriatelyaccording to translucent substrate 11-forming materials, useenvironments, and the like.

In organic EL lighting panel substrate 10 of the present embodiment,translucent substrate 11 is formed of a single-layered substrate.However, the present invention is not limited to this example and, forexample, the translucent substrate may be formed of a plurality oflayers.

Transparent electrode 12 can be formed by a conventionally known methodsuch as sputtering or the like using a transparent conductive thin film,for example. Examples of the material for forming the transparentconductive thin film include ITO, ZnO, IZO (registered trademark,indium-zinc oxide), IGZO (indium-gallium-zinc oxide), GZO (gallium-zincoxide), and SnO₂.

Specific examples of the material for forming auxiliary electrode 13include Cr (chromium), Cu (copper), Al (aluminum), Ag (silver), Au(gold), Mo (molybdenum), W (tungsten), Ni (nickel), and the alloysthereof. Examples of the alloy include Al—Mo (aluminum-molybdenum),Al—Nd (aluminum-neodymium), Al—Ni (aluminum-nickel), and Mo—Nb(molybdenum-niobium). Among them, a three-layered laminate ofMo—Nb/Al—Nd/Mo—Nb (MAM) is particularly preferable from the view pointof environment-friendliness, reliability, and general versatility(price). The volume resistivity of the auxiliary electrode 13-formingmaterial is, at 20° C., preferably in the range from 1.59×10⁻⁸ to13×10⁻⁸ Ω·m and more preferably in the range from 1.59×10⁻⁸ to 7×10⁻⁸Ω·m. The lower limit of the volume resistivity, “1.59×10⁻⁸ Ω·m”, is theresistance of Ag (silver) having the lowest resistance. It is preferablethat the volume resistivity is in the above-described range because itincreases the effect of reducing the wiring resistance at thetransparent electrode side. When the MAM is used as an auxiliaryelectrode, the thicknesses of the respective layers are preferably inthe range from 30 nm to 50 nm, in the range from 200 nm to 500 nm, andin the range from 30 nm to 50 nm in this order.

By arranging auxiliary electrode 13 of this type on transparentelectrode 12, auxiliary electrode 13 is electrically connected totransparent electrode 12. The auxiliary electrode 13 is provided withina surface of organic EL lighting panel substrate 10 in a grid pattern.Therefore, when organic EL lighting panel is formed using organic ELlighting panel substrate 10, the wiring resistance at the transparentelectrode 12 side can be reduced, and the luminance uniformity andchromaticity uniformity within a surface of organic EL lighting panelcan be improved. Note here that, the arrangement pattern of theauxiliary electrode is not limited to a grid pattern and can be anypattern as long as the wiring resistance at the transparent electrodeside can be reduced. Also, in the present invention, the connection formof the auxiliary electrode and the transparent electrode is not limitedto the above-described connection form, and can be any connection formas long as the auxiliary electrode is electrically connected to thetransparent electrode.

Auxiliary electrode 13 can be patterned as follows. A photolithographystep is performed using an insulating photoresist on transparentelectrode 12, and the resist at an auxiliary electrode-forming part isremoved. A layer of an auxiliary electrode-forming material is formedall over the substrate obtained as described above, and then the resistis removed. Thereby, the auxiliary electrode-forming material is liftedoff except for the auxiliary electrode part, and thereby the auxiliaryelectrode can be patterned. Furthermore, at the time of the exposure inthe photolithography step, insulating layer 14 can be formed on atranslucent substrate at the position corresponding to an upperelectrode lead-out part. The formation of insulating layer 14 can alsobe performed by causing an insulating photoresist remain at the positioncorresponding to an upper electrode lead-out part using a slit photomasksuch as a gray-tone mask or a phase shift mask such as a halftone mask.

An organic EL lighting panel substrate of the present embodiment may bein a form in which it further includes an auxiliary electrode-insulatingmember and the auxiliary electrode is covered with the auxiliaryelectrode-insulating member. FIG. 2 is a cross sectional view showing anexample of this form. As shown in FIG. 2, organic EL lighting panelsubstrate 10A of this example has the same configuration as organic ELlighting panel substrate 10 shown in FIG. 1 except that organic ELlighting panel substrate 10A includes auxiliary electrode-insulatingmember 15, and auxiliary electrode 13 is covered with auxiliaryelectrode-insulating member 15 except for the part that is in contactwith transparent electrode 12.

Auxiliary electrode-insulating member 15 has a function of preventingthe diffusion of auxiliary electrode 13 and a function of insulating anauxiliary electrode from an organic EL layer and an upper electrodeformed above the auxiliary electrode at the time of forming an organicEL lighting panel using organic EL lighting panel substrate 10A.

Examples of the material forming auxiliary electrode-insulating member15 include inorganic materials and polymeric materials, and it ispreferable that auxiliary electrode-insulating member 15 is formed by aphotolithography step using an insulating photoresist. Examples of theinsulating photoresist include photosensitive polymeric materials suchas acrylic materials, novolac materials, polyimide materials, and thelike. The thickness of auxiliary electrode-insulating member 15 is, forexample, about 500 nm to 1 μm. In the case where an insulating member isformed using the insulating photoresist, for example, the insulatingmember can be formed only by a photolithography step without performinga photo-etching step, and therefore the load from steps can be reduced.

Auxiliary electrode-insulating member 15 can be patterned on auxiliaryelectrode 13 by applying an insulating photoresist all over thesubstrate and then exposing from the back surface. Since the light isblocked at a metal auxiliary electrode part, the exposure pattern isself-aligned, and auxiliary electrode-insulating member 15 can becompletely patterned without manufacturing or using an expensivephotomask. Thereafter, the substrate is subjected to the development andpost-baking to manufacture an organic EL lighting panel substrate.

An organic EL lighting panel substrate having the configuration of thepresent embodiment can be manufactured without patterning transparentelectrode 12. Therefore, the number of photolithography steps can bereduced, and defects and problems due to remaining resist residues andforeign matters on a substrate can be suppressed as compared to aconventional organic EL lighting panel substrate.

Next, an example of a method for manufacturing organic EL lighting panelsubstrate 10A will be described with reference to FIGS. 3A and 3B. Notehere that the method for manufacturing organic EL lighting panelsubstrate 10A is not limited to the following example.

First, as shown in FIG. 3A(a), transmissive substrate 11 is provided.Then, as shown in FIG. 3A(b), transparent electrode 12 formed of ITO orthe like is formed on a surface of translucent substrate 11 bysputtering, for example (transparent electrode formation step). Next, asshown in FIG. 3A(c), an insulating photoresist is applied. Then, asshown in FIGS. 3A(d) and (e), the substrate is exposed through aphotomask followed by the development and baking to pattern thephotoresist. FIGS. 3A(d) and (e) show the case in which the photoresistis a positive type photoresist and the photomask is a gray-tone maskincluding an exposure part for the part corresponding to an auxiliaryelectrode-forming part, a light-blocking part for the part correspondingto an upper electrode lead-out part, and a gray-tone part for the partcorresponding to a lift-off part (part on which an auxiliary electrodeis not formed). The use of the gray-tone mask makes it possible toattain the thickness of the insulating photoresist at the partcorresponding to the upper electrode lead-out part thicker than thethickness of the photoresist at the part corresponding to the lift-offpart. Here, since the photoresist used in the present invention can beany photoresist as long as the resist can be removed at an auxiliaryelectrode-forming part, the photoresist is not limited to a positivetype and can be a negative type. In the case of using a negative typephotoresist, a gray-tone mask including a light-blocking part for thepart corresponding to an auxiliary electrode-forming part, an exposurepart for the part corresponding to an upper electrode lead-out part, anda gray-tone part for the part corresponding to a lift-off part (part onwhich an auxiliary electrode is not formed) may be used as a photomask.Furthermore, the photomask is not limited to a slit photomask such as agray-tone mask, and a phase shift mask such as a halftone mask or thelike may be used. Next, as shown in FIG. 3A(f), after forming a layer ofan auxiliary electrode-forming material all over the substrate (filmformation), the photoresist is removed. Thereby, as shown in FIG. 3A(g),the auxiliary electrode-forming material is lifted off except for theauxiliary electrode-forming part, and thus the auxiliary electrode canbe patterned (auxiliary electrode formation step). Furthermore, the useof a gray-tone mask or the like at the time of the exposure (FIG. 3A(d))allows the insulating photoresist to remain at the positioncorresponding to the upper electrode lead-out part, and therebyinsulating layer 14 in the present invention can be formed (insulatinglayer formation step).

Next, as shown in FIG. 3B(h), an insulating photoresist is applied allover translucent substrate 11 at the side on which auxiliary electrode13 is formed. Then, as shown in FIG. 3B(i), translucent substrate 11 isexposed from the back surface (the surface opposite to thephotoresist-applied surface), and the development is performed as shownin FIG. 3B(j). At this time, since the light is blocked at the part onwhich auxiliary electrode 13 is formed, the photoresist can be patternedto suit the auxiliary electrode 13-forming part without using aphotomask or the like. Then, as shown in FIG. 3B(k), by baking thesubstrate after development (post-bake), auxiliary electrode-insulatingmember 15 is formed. The thickness of auxiliary electrode-insulatingmember 15 is preferably in the range from 0.5 μm to 1.5 μm. In thismanner, for example, organic EL lighting panel substrate 10A shown inFIG. 2 can be manufactured. Note here that the method for manufacturingorganic EL lighting panel substrate 10A is not limited to this example.

Embodiment 2

An organic EL lighting panel of the present embodiment is an example ofan organic EL lighting panel using organic EL lighting panel substrate10A of Embodiment 1 shown in FIG. 2. FIG. 4 shows the configuration ofan organic EL lighting panel of the present embodiment. FIG. 4(a) is aplan view of an organic EL lighting panel of the present invention. FIG.4(b) is a cross sectional view of the organic EL lighting panel shown inFIG. 4(a) as viewed from the line II-II.

As shown in FIG. 4, organic EL lighting panel 100 of the presentembodiment includes organic EL lighting panel substrate 10A, organic ELlayer 111, and upper electrode 112 as main components. In organic ELlighting panel substrate 10A, auxiliary electrode 13 is covered withauxiliary electrode-insulating member 15 except for the part that is incontact with transparent electrode 12. Organic EL layer 111 and upperelectrode 112 are laminated on transparent electrode 12 and auxiliaryelectrode-insulating member 15 in this order. Since organic EL lightingpanel 100 uses the organic EL lighting panel substrate 10A shown in FIG.2, the effect described in Embodiment 1 can be achieved.

Details of translucent substrate 11, transparent electrode 12, andauxiliary electrode 13 are the same as those described above(hereinafter, the same applies). Transparent electrode 12 serves as ananode, for example.

Organic EL layer 111 includes: a light-emitting layer that contains anorganic electroluminescence substance; a hole transport layer and anelectron transport layer that sandwich the light-emitting layer; and ahole injection layer and an electron injection layer that sandwich thehole transport layer and the electron transport layer, for example.Furthermore, organic EL layer 111 may further include a carrier-blockinglayer that blocks a hole or an electron and improves the luminousefficiency, for example. Organic EL layer 111 is a laminate in which ahole injection layer, a hole transport layer, a light-emitting layer, anelectron transport layer, and an electron injection layer are laminatedfrom the transparent electrode 12 side in this order, for example.

The hole injection layer is provided so as to lower the level of aninjection barrier to a hole injected from transparent electrode 12(anode) to organic EL layer 111 and to ease the difference in the energylevel between the anode and the hole transport layer to allow the easyinjection of a hole injected from the anode to the hole transport layer.The hole injection layer is formed of a hole injection layer material.Examples of the hole injection layer material include hole injectionorganic materials. Specific examples thereof include copperphthalocyanine and arylamine derivatives such as starburst type aromaticamine and the like. The hole injection organic material may be amaterial chemically doped with an inorganic matter such as vanadiumpentoxide, molybdenum trioxide, or the like or an organic matter such asF4-TCNQ or the like for further lowering the level of the injectionbarrier and the drive voltage, for example.

The hole transport layer is preferably formed of a hole transport layermaterial. The hole transport layer material has right amount ofionization potential for increasing the hole mobility to thelight-emitting layer and, at the same time, has an electron affinity forpreventing the leak of an electron from the light-emitting layer.Specific examples of the hole transport layer material includetriphenyldiamines and starburst type aromatic amine. Examples of thetriphenyldiamines include bis(di(p-tolyl)aminophenyl)-1,1-cyclohexane,4,4′-bis(m-tolylphenylamino)biphenyl (TPD), andN,N′-diphenyl-N-N-bis(1-naphthyl)-1,1′-biphenyl)-4,4′-diamine (α-NPD).

The light-emitting layer recombines electrons and holes injected fromelectrodes to emit fluorescence, phosphorescence, or the like. Thelight-emitting layer contains a light-emitting material. Examples of thelight-emitting material include low-molecular weight compounds such astris(8-quinolinol)aluminum complex (Alq₃), bis diphenyl vinyl biphenyl(BDPVBi), 1,3-bis(p-t-butylphenyl-1,3,4-oxadiazolyl)phenyl (OXD-7),N,N′-bis(2,5-di-t-butylphenyl)perylene tetracarboxylic diimide (BPPC),1,4-bis(N-p-tolyl-N-4-(4-methyl styryl)phenylamino)naphthalene, and thelike; and high-molecular weight compounds such as a polyphenylenevinylene polymer and the like.

Furthermore, for example, the light-emitting material is formed of atwo-component system of a host and a dopant and may be a material inwhich excited-state energy generated in a host molecule is transferredto a dopant molecule to cause the dopant molecule to emit light.Examples of such a light-emitting material include the above-describedlight-emitting materials, the electron transport layer materials thatwill be described below, and the above-described hole transport layermaterials. Specific examples thereof include materials obtained bydoping hosts with dopants according to the following combinations:

Host: a quinolinol metal complex such as Alq₃ or the likeDopant: a quinacridone derivative such as4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM),2,3-quinacridone, or the like or a coumarin derivative such as3-(2′-benzothiazole)-7-diethylaminocoumarin or the like;Host: an electron transport materialbis(2-methyl-8-hydroxyquinoline)-4-phenylphenol-aluminum complexDopant: a condensed polycyclic aromatic compound such as perylene or thelike;Host: a hole transport layer material4,4′-bis(m-tolylphenylamino)biphenyl (TPD)Dopant: rubrene or the like; andHost: a carbazole compound such as 4,4′-biscarbazolylbiphenyl (CBP),4,4′-bis(9-carbazolyl)-2,2′-dimethylbiphenyl (CDBP), or the likeDopant: a platinum complex or an iridium complex such as tris-(2phenylpyridine)iridium (Ir(ppy)₃),bis(4,6-di-fluorophenyl)-pyridinate-N,C2)iridium(picolinate) (FIr(pic)),bis(2-2′-benzothienyl)-pyridinate-N,C3iridium(acetylacetonate)(Btp₂Ir(acac)), tris-(picolinate)iridium (Ir(pic)₃),bis(2-phenylbenzothiozolate-N,C2)iridium(acetylacetonate) (Bt₂Ir(acac)), or the like.

The light-emitting material can be selected appropriately according to adesired color of the light to be emitted from an organic EL lightingpanel, for example. Specific examples of the selection are as follows:

in the case of green light emission:

Host: Alq₃

Dopant: quinacridone, coumarin, or the like or

Host: CBP

Dopant: Ir(ppy)₃ or the like;in the case of blue light emission:Host: 4,4′-bis(2,2-diphenylethenyl)-1,1′-biphenyl (DPVBi)Dopant: perylene, a distyrylallylene derivative or the like or

Host: CBP

Dopant: FIr(pic) or the like;in the case of green to blue-green light emission:

Host: Alq₃

Dopant: OXD-7 or the like;in the case of red to orange light emission:

Host: Alq₃ Dopant: DCM or

4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran(DCJTB) or

Host: CBP

Dopant: Ir (pic)₃ or the like; andin the case of yellow light emission:

Host: Alq₃

Dopant: rubrene or

Host: CBP

Dopant: Bt₂Ir(acac) or the like.

An example of the light-emitting layer of emitting white light includesa three-layered layer that contains light-emitting materials emittingred, green, and blue. In addition to this, examples of thelight-emitting layer of emitting white light include a two-layered layerthat contains light-emitting materials emitting complementary colorssuch as blue and yellow, and the like and a single-layered layerobtained by forming a layer using the light-emitting materials of therespective colors by multiple co-evaporation or the like so that thelight-emitting materials of the respective colors are mixed.Furthermore, a layer obtained by planarly aligning, in order, finepixels of red, blue, green, and the like of the light-emitting materialsthat form the respective layers of the three-layered layer and thetwo-layered layer may be used as the light-emitting layer emitting whitelight.

The electron transport layer is preferably formed of an electrontransport layer material. The electron transport layer material hasright amount of ionization potential for increasing the electronmobility to the light-emitting layer and, at the same time, has anelectron affinity for preventing the leak of a hole from thelight-emitting layer. Specific examples of the electron transport layermaterial include organic materials such as oxadiazole derivatives suchas 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (Bu-PBD),OXD-7, and the like; triazole derivatives; quinolinol metal complexes;and the like. Furthermore, the electron transport layer material may bea material obtained by causing organic material to be chemically dopedwith an electron-donating substance such as an alkali metal such aslithium or the like, for example.

The electron injection layer is provided to ease the difficulty inelectron injection from the cathode to the electron transport layer dueto a great difference in energy between the work function of a metalmaterial such as aluminum or the like used for forming a cathode and theelectron affinity (LUMO level) of the electron transport layer, forexample. The electron injection layer is preferably formed of anelectron injection layer material. An example of the electron injectionlayer material includes a material with a low work function, andspecific examples thereof include fluorides and oxides of alkali metalssuch as lithium, cesium, and the like and alkali earth metals such ascalcium and the like; magnesium-silver; and lithium aluminum alloy.

An example of the carrier-blocking layer includes a hole-blocking layer.The hole-blocking layer is provided between the light-emitting layer andthe electron transport layer for blocking a hole passing through thelight-emitting layer without involving in light emission and increasingthe recombination probability in the light-emitting layer. Examples ofmaterials for forming the hole-blocking layer include2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), triphenyldiaminederivatives, and triazole derivatives.

The thickness of organic EL layer 111 is not particularly limited, and,for example, the thicknesses of the respective layers that form organicEL layer 111 are each in the range from 1 nm to 500 nm The thickness ofthe total of the respective layers is, for example, in the range from100 nm to 1000 nm.

The method for forming organic EL layer 111 can be, for example, aconventionally known method. For example, in the case where thelight-emitting layer is formed of the above-described low-molecularweight compound (low-molecular weight organic EL material), for example,the light-emitting layer can be formed by a vacuum evaporation methodutilizing resistance heating of the low-molecular weight organic ELmaterial. Furthermore, for example, in the case where the light-emittinglayer is formed of the above-described high-molecular weight compound(high-molecular weight organic EL material), for example, thelight-emitting layer may be formed by applying the high-molecular weightorganic EL material by a slit coating method, a flexographic printingmethod, an ink-jet method, or the like.

Upper electrode 112 is an electrode paired with transparent electrode12. In the case where transparent electrode 12 serves as an anode, theupper electrode serves as a cathode. Upper electrode 112 may betranslucent or not translucent, for example. In the case where upperelectrode 112 is an electrode that is not translucent, a lightproofmaterial such as a metal thin film such as aluminum, silver, or the likecan be used for upper electrode 112, for example. The electrode of thistype is preferable because it allows the light emitted toward the upperelectrode 112 side to be reflected to the transparent electrode 12 sideduring the light emission of organic EL layer 111 and suppresses thedecrease in the amount of emitting light from a light emitting surface.The thickness of upper electrode 112 is not particularly limited. Inconsideration of the voltage drop due to wiring resistance, it ispreferable that the upper electrode 112 is thick, and the thickness ofupper electrode 112 can be set, for example, in the range from 50 nm to300 nm On the other hand, in the case where upper electrode 112 is atranslucent electrode, for example, upper electrode 112 can be formedusing a material similar to those for forming transparent electrode 12.The electrode of this type allows the manufacture of an organic ELelement that becomes transparent when it is not emitting the light, forexample. The method for forming upper electrode 112 can be, for example,a conventionally known method. In the case where upper electrode 112 isformed of a metal such as aluminum or the like, upper electrode 112 canbe formed by vacuum evaporation utilizing resistance heating of themetal, electron beam (EB) evaporation, or sputtering. Since an organicEL lighting panel of the present invention includes a connection partwith an external wiring member, an end of transparent electrode 12 andan end of upper electrode 112 may be extended.

Organic EL lighting panel 100 is formed in the above-described manner.Note here that, in the present invention, for cutting off elements in anorganic EL lighting panel from the outside world, the elements may besealed using a conventionally known blocking material, for example.

Organic EL lighting panel 100 can be applied, for example, to an organicEL lighting device; a backlight of a liquid crystal display or the like;or the like, and is preferably applied to an organic EL lighting device,a backlight, or the like that requires a big panel, specifically, apanel size of 10 cm×10 cm, for example. Note here that, an organic ELlighting panel of the present invention is not limited to theabove-described usage but can be applied to a wide range of field.

Embodiment 3

An organic EL lighting panel substrate of the present embodimentincludes a transparent electrode arranged all over a surface of atranslucent substrate and includes an auxiliary electrode patternedbetween the translucent substrate and the transparent electrode.Furthermore, an organic EL lighting panel substrate of the presentembodiment is an example of an organic EL lighting panel substrate inwhich a layer formed of the same material as an auxiliary electrode isarranged on the translucent substrate at the position corresponding toan upper electrode lead-out part and an insulating layer is arranged onthe transparent electrode at the positions corresponding to theauxiliary electrode and the upper electrode lead-out part. FIG. 5 showsthe configuration of organic EL lighting panel substrate 20 of thepresent embodiment.

Next, an example of a method for manufacturing organic EL lighting panelsubstrate 20 will be described with reference to FIGS. 6A and 6B. Notehere that the method for manufacturing organic EL lighting panelsubstrate 20 is not limited to the following example.

First, as shown in FIG. 6A(a), translucent substrate 11 is provided.Next, as shown in FIG. 6A(b), a photoresist is applied. Then, as shownin FIGS. 6A(c) and (d), the substrate is exposed through a photomaskfollowed by the development and baking to pattern the photoresist. Atthis time, the resist at the positions corresponding to an auxiliaryelectrode-forming part and an upper electrode lead-out part is removed.Next, as shown in FIG. 6A(e), after forming a layer of an auxiliaryelectrode-forming material all over the substrate, the photoresist isremoved. Thereby, as shown in FIG. 6A(f), the auxiliaryelectrode-forming material is lifted off except for the auxiliaryelectrode-forming part and the upper electrode lead-out part, and thusauxiliary electrode 13 can be patterned (auxiliary electrode formationstep).

Next, as shown in FIG. 6B(g), transparent electrode 12 formed of ITO orthe like is formed by sputtering all over translucent substrate 11 atthe side on which auxiliary electrode 13 is formed, for example(transparent electrode formation step). Next, as shown in FIG. 6B(h), aninsulating photoresist is applied to transparent electrode 12. Then asshown in FIG. 6B(i), translucent substrate 11 is exposed from the backsurface (the surface opposite to the photoresist-applied surface), andthe development is performed as shown in FIG. 6B(j). At this time, sincethe light is blocked at the position on which auxiliary electrode 13 isformed and the position corresponding to the upper electrode lead-outpart, the photoresist can be patterned to suit the light-blocking partwithout using a photomask. Then, as shown in FIG. 6B(k), by baking thesubstrate after development (post-bake), insulating layer 14 andauxiliary electrode-insulating member 15 are formed (insulating layerformation step). In this manner, for example, organic EL lighting panelsubstrate 20 shown in FIG. 5 can be manufactured.

While four photomasks and twenty-two steps were required for themanufacturing of an organic EL lighting panel substrate shown in FIGS.9A to C, only one photomask and eleven steps are required for theabove-described manufacturing method. Note here that, the method formanufacturing organic EL lighting panel substrate 20 is not limited tothis example.

Embodiment 4

An organic EL lighting panel substrate of the present embodimentincludes a transparent electrode patterned on a surface of a translucentsubstrate and includes an auxiliary electrode patterned between thepatterned transparent electrode. Furthermore, an organic EL lightingpanel substrate of the present embodiment is an example of an organic ELlighting panel substrate in which a layer formed of the same material asan auxiliary electrode is arranged on the translucent substrate at theposition corresponding to an upper electrode lead-out part and aninsulating layer is arranged on the transparent electrode at thepositions corresponding to the auxiliary electrode and the upperelectrode lead-out part. FIG. 7 shows the configuration of organic ELlighting panel substrate 30 of the present embodiment.

Next, an example of a method for manufacturing organic EL lighting panelsubstrate 30 will be described with reference to FIGS. 8A and 8B. Notehere that the method for manufacturing an organic EL lighting panelsubstrate 30 is not limited to the following example.

First, as shown in FIG. 8A(a), translucent substrate 11 is provided.Next, as shown in FIG. 8A(b), a layer of an auxiliary electrode-formingmaterial is formed on a surface of translucent substrate 11. Next asshown in FIG. 8A(c), a photoresist is applied. Then, as shown in FIG.8A(d) and (e), the substrate is exposed through a photomask followed bythe development and baking to pattern the photoresist. At this time, byetching the layer of the auxiliary electrode-forming material, auxiliaryelectrode 13 can be patterned as shown in FIG. 8A(f) (auxiliaryelectrode formation step). By performing the patterning so as to causethe photoresist to remain at the position corresponding to an upperelectrode lead-out part, a conductive layer can be formed at theposition corresponding to the upper electrode lead-out part.

Next, as shown in FIG. 8B(g), after forming a layer of a transparentelectrode-forming material such as ITO or the like all over translucentsubstrate 11 at the side on which auxiliary electrode 13 is formed bysputtering, for example, the photoresist is removed. Thereby, as shownin FIG. 8B(h), a transparent electrode at an auxiliary electrode-formingpart and a conductive layer-forming part is lifted off, and thustransparent electrode 12 can be patterned (transparent electrodeformation step). Next, as shown in FIG. 8B(i), an insulating photoresistis applied all over translucent substrate 11 at the side on whichtransparent electrode 12 and the like are formed. Then as shown in FIG.8B(j), translucent substrate 11 is exposed from the back surface (thesurface opposite to the photoresist-applied surface), and thedevelopment is performed as shown in FIG. 8B(k). At this time, since thelight is blocked at the position on which auxiliary electrode 13 isformed and the position corresponding to the upper electrode lead-outpart, the photoresist can be patterned to suit the light-blocking partwithout using a photomask. Then, as shown in FIG. 8B(l), by baking thesubstrate after development (post-bake), insulating layer 14 andauxiliary electrode-insulating member 15 are formed (insulating layerformation step). In this manner, for example, organic EL lighting panelsubstrate 30 shown in FIG. 7 can be manufactured.

While four photomasks and twenty-two steps were required for themanufacture of a conventional organic EL lighting panel substrate shownin FIGS. 10A to C, only one photomask and twelve steps are required forthe above-described manufacturing method. Note here that, the method formanufacturing organic EL lighting panel substrate 30 is not limited tothis example.

EXAMPLE

Next, the present invention will be described in more detail withreference to examples of the present invention. However, the presentinvention is not limited to or restricted by the following examples byany means.

Example 1

(1) Manufacture of Organic EL Lighting Panel

As an organic EL lighting panel of the present example, organic ELlighting panel 100 shown in FIG. 4 having a light emitting surface of100 mm×100 mm was manufactured as follows. That is, first, analkali-free glass (thickness: 0.7 mm, produced by Nippon Electric GlassCo., Ltd., OA-10G) was provided as translucent substrate 11. ITO wasformed as transparent electrode 12 on alkali-free glass 11 by sputtering(ITO film 12, thickness: 300 nm). Next, an insulating novolac positivetype photoresist (product name “PFR-7750”, produced by JSR Corporation)was applied in such a manner as to cover ITO film 12, and the patterningwas performed so as to remove the resist at an auxiliaryelectrode-forming part by photolithography. Here, as a mask used at thetime of exposure, a gray-tone mask including an exposure part for thepart corresponding to an auxiliary electrode-forming part, alight-blocking part for the part corresponding to an upper electrodelead-out part, and a gray-tone part for the part corresponding to alift-off part (part on which an auxiliary electrode is not formed) wasused. The use of the gray-tone mask made it possible to attain thethickness of the insulating photoresist at the part corresponding to theupper electrode lead-out part thicker than the thickness of thephotoresist at the part corresponding to the lift-off part.

Next, after forming a layer of auxiliary electrode-forming materials(Mo—Nb/Al—Nd/Mo—Nb (MAM)) by sputtering so as to have the thickness of460 nm (30 nm/400 nm/30 nm), the photoresist was removed (liftoff), andthe auxiliary electrode 13 was patterned so as to be in a grid patternhaving a width of 180 μm and with 5 mm-pitch between the adjacentauxiliary electrodes (auxiliary electrode formation step). At this time,since the photoresist remained thickly at the position corresponding tothe upper electrode lead-out part, insulating layer 14 could be formedby causing the insulating photoresist to remain at the position(insulating layer formation step).

Next, an insulating novolac positive type photoresist (product name“PFR-7750”) was applied all over translucent substrate 11 at the side onwhich auxiliary electrode 13 and insulating layer 14 are formed so as toobtain a layer having a thickness of 1.2 μm, translucent substrate 11was exposed from the back surface (the surface opposite to thephotoresist-applied surface), and the development was performed. At thistime, since the light was blocked at the parts on which auxiliaryelectrode 13 and insulating layer 14 are formed, the photoresist couldbe patterned to suit an auxiliary electrode 13-forming part and aninsulating layer 14-forming part without using a photomask or the like.Then, by baking the substrate after development (post-bake), auxiliaryelectrode-insulating member 15 was formed. The thickness and width ofauxiliary electrode-insulating member 15 were respectively 0.85 μm(residual film ratio: 71%) and 200 μm. In this manner, an organic ELlighting panel substrate with ITO film 12 as an anode (transparentelectrode) and MAM as auxiliary electrode 13 was manufactured.

Next, organic EL layer 111 was formed on ITO film 12 and auxiliaryelectrode-insulating member 15 by a vacuum evaporation method, andfinally, aluminum cathode 112 was formed on organic EL layer 111 by avacuum evaporation method. In this manner, organic EL lighting panel 100shown in FIG. 4 was manufactured. Organic EL layer 111 was a laminate inwhich a hole injection layer, a hole transport layer, a light-emittinglayer, a hole-blocking layer, an electron transport layer, and anelectron injection layer were laminated in this order from the ITO film12 side. The materials for forming the respective layers in the laminatewere as follows:

Hole injection layer: Cu-Pc (copper phthalocyanine)Hole transport layer: α-NPD (N,N′-diphenyl-N-N-bis(1-naphthyl)-1,1′-biphenyl)-4,4′-diamineLight-emitting layer:

-   -   Host: CBP (4,4′-biscarbazolylbiphenyl)    -   Dopant: Ir(ppy)₃ (tris-(2 phenylpyridine)iridium complex),        Btp₂Ir(acac)        (bis(2-(2′-benzo(4,5-α)thienyl)pyridinate-N,C2′)(acetylacetonate)iridium        complex), FIr(pic)        ((bis(4,6-di-fluorophenyl)-pyridinate-N,C2′)picolinateiridium        complex)        Hole-blocking layer: BCP        (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)        Electron transport layer: Alq₃        Electron injection layer: LiF

(2) Characteristic Evaluation

(2-1) Luminance Uniformity Evaluation

An organic EL lighting panel of the present example was turned on with aconstant-current of 25 A/m² as a drive current. The drive voltage was4.5 V and the luminance was 1000 cd/m². The luminance uniformity of thisorganic EL lighting panel was evaluated as follows. That is, theluminance values at nine points within a surface of this organic ELlighting panel were measured and the highest luminance value and thelowest luminance value among the luminance values at the nine pointswere substituted into the following equation (I) to calculate theluminance uniformity (hereinafter, the same applies). The lower theluminance uniformity value (%) is, the higher the luminance uniformitywithin a surface of an organic EL lighting panel becomes. The luminanceuniformity of this organic EL lighting panel was 3%.

Luminance uniformity (%)=(highest luminance value−lowest luminancevalue)/highest luminance value×100   (I)

(2-2) Continuous Lighting Evaluation

This organic EL lighting panel was continuously lighted at the samecurrent density as (2-1) (n=10). As a result, after continuous lightingof 10000 hours, all organic EL lighting panels were lighted withstability.

Comparative Example 1

(1) Manufacture of Organic EL Lighting Panel

An organic EL lighting panel of the present comparative example wasmanufactured in the same manner as in Example 1 except that auxiliaryelectrode 13 was not formed.

(2) Characteristic Evaluation

(2-1) Luminance Uniformity Evaluation

An organic EL lighting panel of the present comparative example wasturned on with a constant-current of 25 A/m² as a drive current. Thedrive voltage was 5.6 V and the luminance was 810 cd/m². The luminanceuniformity of this organic EL lighting panel was 35%.

(2-2) Continuous Lighting Evaluation

This organic EL lighting panel was continuously lighted at the samecurrent density as (2-1) (n=10). As a result, within 1000 hours, shortcircuits were caused in five organic EL lighting panels and the lightwent off.

Comparative Example 2

(1) Manufacture of Organic EL Lighting Panel

An organic EL lighting panel of the present comparative example wasmanufactured according to the steps shown in FIGS. 9A to C.

(2) Characteristic Evaluation

(2-1) Luminance Uniformity Evaluation

An organic EL lighting panel of the present comparative example wasturned on with a constant-current of 25 A/m² as a drive current. Thedrive voltage was 4.8 V and the luminance was 970 cd/m². The luminanceuniformity of this organic EL lighting panel was 4%.

(2-2) Continuous Lighting Evaluation

This organic EL lighting panel was continuously lighted at the samecurrent density as (2-1) (n=10). As a result, within 1000 hours, shortcircuits were caused in four organic EL lighting panels and the lightwent off.

According to the above-described results, organic EL lighting panels ofExample 1 showed high luminance uniformity within the surfaces thereof,prevented short circuits, and showed high reliability. In contrast,organic EL lighting panels of Comparative Example 1 showed low luminanceuniformity within the surfaces thereof, caused short circuits, andshowed low reliability. Furthermore, with respect to organic EL lightingpanels of Comparative Example 2, since resist residues and foreignmatters remain on a substrate due to a repetition of a photolithographystep and the like, defects/problems such as a short circuit and the likeare caused frequently in an organic EL panel, and therefore the organicEL lighting panels of Comparative Example 2 showed significantly lowyields and reliability.

As described above, according to an organic EL lighting panel substrate,a method for manufacturing an organic EL lighting panel substrate, andan organic EL lighting panel using the organic EL lighting panelsubstrate of the present invention, it is possible to greatly reducemanufacturing steps, improve the luminance uniformity and chromaticityuniformity within a surface of an organic EL lighting panel, and achievethe excellent yield and reliability. This is also effective in the caseof forming multiple organic EL lighting panels on a big transparentsubstrate, and the effect becomes more significant. Also, since thenumber of photo-etching steps and photolithography steps can be reduced,the cycle time can be reduced and the cost can be reduced. Furthermore,in a conventional organic EL lighting panel, since there is a differencein level between a translucent substrate and an ITO part at the end(edge) of a transparent conductive film such as ITO or the like, a shortcircuit was likely caused between the end (edge) and a cathode formed onan organic layer. For preventing the short circuit, a so-called edgecover (or insulator), which is a cover for a difference in level ofresists, has been formed in the subsequent step. On the other hand,since the structure of the present invention does not require the edgecover, the reduction of steps and row costs can be achieved as well asthe improvement of yield because of less occurrence of short circuit canbe achieved. Furthermore, since the number of photo-etching steps can bereduced, it is possible to reduce an etching waste liquid due to wetetching and supply an environmentally-friendly organic EL lighting panelsubstrate. Also, by reducing the number of photolithography steps, it ispossible to reduce defects/problems such as a short circuit and the likecaused in an organic EL panel due to a resist residue or the like andimprove the yield. An organic EL lighting panel of the present inventioncan be applied, for example, to an organic EL lighting device; abacklight of a liquid crystal display or the like; or the like. Notehere that the usage of an EL lighting panel of the present invention isnot limited to the above-described usage but can be applied to a widerange of field.

The invention of the present application was described above withreference to the embodiments and examples. However, the invention of thepresent application is not limited to the above-described embodimentsand examples. Various changes that can be understood by those skilled inthe art can be made in the configurations and details of the inventionof the present application within the scope of the invention of thepresent application.

This application claims priority from Japanese Patent Application No.2012-182746 filed on Aug. 21, 2012. The entire disclosure of thisJapanese patent application is incorporated herein by reference.

EXPLANATION OF REFERENCE NUMERALS

-   10, 10A, 20, and 30 organic EL lighting panel substrate-   11 translucent substrate-   12 transparent electrode (ITO)-   13 auxiliary electrode-   14 insulating layer-   15 auxiliary electrode-insulating member-   100 organic EL lighting panel-   111 organic EL layer-   112 upper electrode

1. A method for manufacturing an organic EL lighting panel substratecomprising: a transparent electrode formation step of forming atransparent electrode on a surface of a translucent substrate; anauxiliary electrode formation step of forming an auxiliary electrode soas to be electrically connected to the transparent electrode; and aninsulating layer formation step of forming an insulating layer at aposition corresponding to an electrode lead-out part of an upperelectrode of an organic EL layer that forms an organic EL lightingpanel, the upper electrode being provided above the translucentsubstrate in such a manner as to face the transparent electrode.
 2. Themethod according to claim 1, wherein in the transparent electrodeformation step, a conductive layer is formed at the positioncorresponding to the electrode lead-out part, and in the insulatinglayer formation step, the insulating layer is formed in such a manner asto cover the conductive layer.
 3. The method according to claim 1,wherein in the auxiliary electrode formation step, the auxiliaryelectrode is formed by photolithography using a insulating photoresist,and the insulating layer formation step is the same step as a step offorming a layer of the photoresist in the auxiliary electrode formationstep.
 4. The method according to claim 1, wherein in the auxiliaryelectrode formation step, a conductive layer is formed at the positioncorresponding to the electrode lead-out part, and in the insulatinglayer formation step, the insulating layer is formed in such a manner asto cover the conductive layer.
 5. The method according to claim 4,wherein the insulating layer formation step is a photolithography stepwith the conductive layer formed in the auxiliary electrode formationstep as a photomask.
 6. An organic EL lighting panel substrate producedby the method according to claim
 1. 7. An organic EL lighting panelcomprising: an organic EL lighting panel substrate; an organic EL layer;and an upper electrode, wherein the organic EL lighting panel substrateis the organic EL lighting panel substrate according to claim 1, and theorganic EL layer and the upper electrode are provided on the transparentelectrode in this order.
 8. An organic EL lighting device comprising:the organic EL lighting panel according to claim
 7. 9. The methodaccording to claim 2, wherein in the auxiliary electrode formation step,the auxiliary electrode is formed by photolithography using a insulatingphotoresist, and the insulating layer formation step is the same step asa step of forming a layer of the photoresist in the auxiliary electrodeformation step.
 10. An organic EL lighting panel substrate produced bythe method according to claim
 2. 11. An organic EL lighting panelsubstrate produced by the method according to claim
 3. 12. An organic ELlighting panel substrate produced by the method according to claim 4.13. An organic EL lighting panel substrate produced by the methodaccording to claim 5.